Lubricating device for sewing machines



NOV. 3, 1953 E 2,657,659

LUBRICATING DEVICE FOR SEWING MACHINES Filed March 26, 1951 \m//////////, I i I x I f d A INVENTOB (Ev/thaw WITNESS. I

ATTORNEY Patented Nov. 3, 1%53 UNITED STATES EVICE FOR SEWING LUBRICATING D MA CHINES Arthur N. Hale, Stratford, Conn., assignor to The Singer Manufacturing Company,

Elizabeth,

N. J., a corporation of New Jersey Application March 26, 1951, Serial No. 217,571

4 Claims.

This invention relates to improvements in sewing machine lubricating systems and more particularly to an improved needle-bar crank oiling system.

While it is known in the sewing machine art to provide forced lubrication systems which automatically lubricate the necessary bearing surfaces in a continuousfashion, such systems are costly and are not used on all existing machines. With machines not automatically lubricated, it is common practice by sewing machine operators to introduce lubricant at various points on the machines at suitable intervals. of modern high speed sewing machine mechanisms', as for instance the crank-pin connection with the needle-bar driving link, a direct application of lubricant at intervals is not satisfactory because the centrifugal forces which are developed during operation have the effect of continuously removing the lubricant.

The patent of Zonis No. 2,387,968, October 30, 1945, discloses one form ofconstruction whereby lubricant which is periodically introduced may be delivered to a needle bar driving link in a substantially continuous fashion, and the present invention has for an object to provide an improved lubricating system of simple and economical construction for storing and dispensing periodically introduced lubricant to a bearing surface in a gradual and substantially continuous manner.

A further object is to provide a construction of the above nature which may be applied to a sewing machine merely by the substitution of a few parts and without requiring any alteration of the sewing machine frame, thus being especially advantageous in application to existing sewing machines.

'With these and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter described in connection with the accompanying drawings, which illustrate a preferred embodiment of the invention, and in which:

Fig. 1 represents an enlarged vertical section of the bracket-arm head portion of a sewing machine, the section being taken in substantially the vertical plane containing the rotation axis of the needle-bar actuating shaft.

Fig. 2 is a fragmentary sectional view taken substantially along line 22 of Fig. 1, and

Fig. 3 is a fragmentary sectional view taken substantially along line 3- -3 of Fig. 1.

The drawings illustrate the invention as applied to a needle-bar actuating crank mechanism of a sewing machine. The machine includes a frame having a hollow bracket-arm II which is formed at its free end with a head 12 adapted to beclosed as by an end cover-plate l3. The hollow bracket-arm is internally formed with At certain parts transverse bearing walls of which one is shown at [4 in Fig. 1. The wall I4 is formed with an aperture l5 which provides a seat for an antifriction'bearing It in which a needle-bar actuating shaft 11 is rotatably journaled.

Journaled for vertical reciprocating movement in suitable bearings as H3, in the head I2 is a needle-bar [9. The stitchforming mechanism including a needle carried by the needle-bar and instrumentalities compleinental to the needle in the formation of stitches do not form a part of this invention and, consequently, these parts have been omitted from the drawings; it being understood that any of the Well known types of stitchforming mechanisms which involve the use of a reciprocatory needle-bar may be used.

Interposed between the rotary actuating shaft l1 and the needle-bar l9 are needle-bar driving connections including a crank 2|, a crank-pin 2| and a connecting link 22. The crank 20, which is secured for rotation with the shaft H by means of set screw 23, is formed with a laterally extending hub portion2 l. The crank is apertured at 25 to accommodate the crank-pin 2| which is secured in place by a set screw 26, and a counterbalance portion 21 is formed on the crank diametrically opposite the crank-pin aperture 25.

The link 22 is formed at its lower extremity with an apertured boss 28 which is journaled on a stud 29 secured to the needle-bar l9. At its upper extremity, the link 22 is formed with an apertured boss 36 which is journaled on the crank-pin 2| by means of anti-friction needle bearings 31. In order to prevent lateral movement of the link 22 endwise of the crank-pin, one side of the boss 30 is adapted to bear against a flanged shoulder 32 formed intermediate the ends of the crank-pin, and a washer 33 is interposed between the boss 30 and the crank 20. The

free extremity of the crank-pin is formed with a flange 34 to which is secured a rotary needlethread take-up element 35.

The lubrication system of this invention contemplates periodic introduction of lubricant through an aperture 36 which is formed in the bracket-arm l i vertically above the rotation axis of shaft H. To that end, a tube 31, of which the'upper end is disposed in the aperture 36, terminates above and at the side of the crank 20 proximate to the Wall M, so that lubricant which is introducedinto the aperture 36 will be fed by gravity between the crank and a dished sheetmetal disk 38 which is pressed on the shouldered extremity'39 of the hub portion 24 of the crank and disposed in spaced relation with the proxi-i if mate face ie of the crank. The disk 38 near its periphery, is dished outwardly away from the.

proximate face 40 of the crank so as to prevent the lubricant from escaping through the bearing 56 and to direct the lubricant from the lower end of the tube 31 toward the hub portion 24 of the crank. An annular undercut recess 4| is formed in the face 46 of the crank, and as shown in Fig. l, wicking 42 ispositioned in the recess; sufficient wicking being provided to extend beyond the recess and into the space between the disk and the crank. It will be understood, therefore, that when the crank is stopped in any position of rota tion, lubricant introduced through the aperture 36 will be directed by the disk 38 and the proxi mate face of the crank toward the hub portion 24. As the lubricant moves gravitationally toward the hub and about the hub in its further downward course, a large portion of the lubricant is absorbed by the wicking, thus providing a reservoir of lubricant which is gradually distributed to the crank-pin bearing during operation of the machine in a manner to be described below.

In order to provide a passage by which to conduct the lubricant from the wicking 42 to the needle bearings 31, the crank-pin 2| is formed with a longitudinal bore 43 which is closed at its inner end by a plug 44. As shown clearly in Fig. 3, the crank-pin 2| is formed with a radial port 45 which is disposed to connect the bore 43 with the widest portion of the annular undercut re..- cess 4| in the crank. A second radial port 46 as illustrated in Fig. 2, is formed in the crank-pin to provide a duct connecting the longitudinal bore 43 and the needle bearing 3 I;

As the shaft l1 and the crank are rotated during operation of the sewing machine, centrifu-gal action forces the lubricant in the wicking 42 outwardly to the widest portion of the undercut recess 4|, at which point the lubricant is forced i through the port into the longitudinal bore 43 and finally through the port 46 to the needle bearing 31. The wicking, in the first instance, tends to give up lubricant in a gradual fashion under the action of the centrifugal forces. In addition, the ports 45 and 46 provide constricted passageways which serve to prevent a sudden flow of lubricant, and insure a continuous flow of small quantities of lubricant to the needle hearing.

The advantages of the present construction are perhaps most readily apparent when considered in connection with installation in an existing machine in the field. First, the counterbalanced crank must be provided with an annular undercut recess and lubricant conducting channels provided in the crank pin. These features may exist in the parts as or ally const uct d or if no th y ve m rely subs it tion o prope y m d P t r a mo t only s mple ma hinin opera ti n econd the wick ng is posit ned in the annular recess as described above, and third the sheet metal disk is pressed on the hub of the crank. In the assembly, no other machining is required and the installation does not require extensive disassembly of other parts of the Sewing machine mechanism.

Having thus set forth the nature of the invention, what I claim herein is:

1. In a sewing machine, a crank-pin lubricate ing system for a needle-bar driving crank mech, anism of the type including a frame, a rotary shaft journaled in said frame, a crank fixed for rotation with said shaft, said crank having a face formed with an annular recess and disposed in a plane substantially transverse to the axis of rotation, said crank having a hub portion extending outwardly from said face, a crank-pin, and a link having at one extremity a bearing journaled on said crank-pin; said lubricating system comprising, a lubricant-directing disk carried by said hub in spaced relation with said crank face, a lubricant conducting passageway terminating vertically above said axis of rotation and between said crank-face and said disk for introducing lubri- 4 cant therebetween, and ducts formed in said crank-pin providing a lubricant conducting passageway from the annular recess to the link bearmg.

2. In a sewing machine having a frame with a bracket-arm, a shaft journaled for rotation in said bracket-arm, a needle-bar supported 1 reciprocatory movement in said bracket- .arm, and a driving connection between said shaft and said needle-bar including a crank carried by said shaft, a crank-pin carried by said crank, and a link having at one extremity a bearing conn cti n w h said cr nk-pin and piYotall-y secured at its other extremity to said needle-bar; m ans for d spens l ricant in a substantially continuous flow to said link bearing comprising, a lubricant conducting passageway xte di g a its pper extremity thr u h said bracket-arm and terminating at its lower extremity vertic lly above the axis of rotation of sa d shaft and a one sid of a d nk, a lubricant collecting member secured for rota.- tion with said shaft and in spaced relation with sai c ank beneath he low r extr mity of id lubricant conducting passageway, said crank formed opposite said lubricant conducting memher with a recess, wicking disposed in said recess, and channels formed in said crank-pin joining the recess in said crank with said link bearing surface- 3. In a sewing machine, a me in luding a wall provided with an opening, a bearing disposed in said opening, a rotary shaft extending throug said p n and iournalc i s d e ng. a crank-m mb ar ied by said shaft at one side of said wall and provided in its face pro mat to s id well wi h n oil-coll cting recess, a. crank-pin carried by said crankme mher, a connection-element journalcd upon said crankepin, a plate-like member disposed between said c ank m mb r and a d well and m unted o ro ate with said shaf a wick disposed in said oil-collecting recess and arranged in contacting relation with one face of said plate-like memb r, an oil-duct in s id fram dispos d with its d li ry end in oil-delivery communica ion wi h sa d p e lik m mber, and oil-conducting means connecting said oil-collecting recess and t e connectionlem nt bear ns up n said cran D111.

4- In a s wing machine, a frame pro id it an oi in roducin aper re, a r tary Shaft .ionr aled hor zontally in s id fram a crank membe a ried by said shaft and pr vid d n its side face with n ann lar il -coll cting recess. a crank-pin carried by said cra-nk menlber, a connection element journaled on said crankrpin, il=conductin passageway throu h said cran p connec ing the crankmin jou nal for said connection el m nt with s d oil-collecting recess, an nnular oil-collect ng di k se ur d f r ro a: i n wi h a rank-member in spac d r la= tion to the rec ssed ide face thereof, and oilnd ting means d p sed betw n said d sk and s i o l-collect n recess, said disk having it flared p pher l p rti n extending outwardly rom s id face and disposed beneath said oil i troducing aperture. ARTHUR N HALE,

eferences Cited in he file o th s p ent UNITED STATES PATENTS 

